Well head for air drilling apparatus



Sept. 4, 1962 D. M. HAMPTON 3,052,300

WELL HEAD FOR AIR DRILLING APPARATUS Filed Feb. 6. 1959 2 Sheets-Sheet lDonald M. Hampton Fig.2 BY

ATTORNEY Sept. 4, 1962 D. M. HAMPTON 3,052,300

WELL HEAD FOR AIR DRILLING APPARATUS Filed Feb. 6. 1959 2 Sheets-Sheet 2INVENTOR Donald M. Humpfon BY Z K {gt/A ATTORNEY see This inventionrelates to a well head for air drilling apparatus, and it concerns moreparticularly a closure device for closing an oil well at the surfaceduring rotary drilling operations in which compressed air is employed asthe drilling fluid.

An object of the invention is to provide a casing head adapted to closean oil well casing at the surface while at the same time permitting freerotative and longitudinal movement of a drill pipe relative thereto.

Another object of the invention is to provide a casing head having meanscapable of providing a seal between an oil well casing and a drill pipemovable rotatively and longitudinally relative to the casing, to therebypermit cuttings to be effectively displaced from a well bore, during adrilling operation, by means of compressed air introduced into the wellbore at the bottom thereof through the kelly and drill pipe.

Another object of the invention is to provide a device for the purposedescribed which is of simple, rugged construction, may be manufacturedinexpensively, and is efficient in operation and durable in use.

The invention will be readily understood by referring to the followingdescription and the accompanying drawing, in which:

FIGURE 1 is an elevational view, partly in section taken on a medianline, of apparatus embodying the invention;

FIGURE 2 is a fragmentary sectional elevational view on an enlargedscale, taken on a median line, showing a portion of the apparatusillustrated in FIGURE 1;

FIGURE 3 is a fragmentary sectional elevational view taken on the line33 of FIGURE 2;

FIGURE 4 is a fragmentary sectional plan view taken on the line 4-4 ofFIGURE 1;

FIGURE 5 is a fragmentary sectional plan view taken on the line 5-5 ofFIGURE 1, the internal bore of a drill pipe being shown in a circulardotted line, and

FIGURE 6 is a fragmentary sectional plan view taken on the line 6-6 ofFIGURE 1.

Referring to the drawing, the numeral 1 designates a well casing, whichis shown fragmentarily. A short casing section or collar 2 is connectedto the well casing 1 and extends upwardly therefrom. The well casing 1and the casing section 2 have flanges 3 and 4, respectively, welded totheir adjacent ends and extending radially outwardly therefrom. Theflanges 3 and 4 are connected in mutually opposed relation to each otherby a plurality of circumferentially spaced bolts 5, which are passedthrough aligned openings provided therefor in the flanges 3 and 4 andhave nuts 6 applied thereto.

The casing section 2 has a side opening 7. A nipple 8, which is insertedin the side opening 7, is welded at one end to the casing section 2 andis threaded externally at its opposite end for engagement by aninternally threaded coupling 9 whereby the casing section 2 may beconnected to a conduit adapted to receive fluids discharged from a wellin which the casing 1 is disposed, along with a drilling fluidintroduced into the well at the bottom thereof.

An annular cover plate 10 has an annular groove 11 in its under side forengagement with the upper edge of the casing section 2. A plurality ofcircumferentially spaced notches 12 are formed in the peripheral edge ofthe cover plate 10 for engagement, respectively, by a plurality of bolts13. The bolts 13 each have an eye 14 on one of its ends, through which apin 15 is passed. The pins 15 are each secured at its ends to a pair oflugs 16, which are connected to the casing section 2 and extend radiallyoutwardly therefrom. The bolts 13 are movable pivotally about the pins15, which are disposed horizontallyv The free ends of the bolts 13 havenuts 17 and washers 13 applied thereto, for engagement with the uppersurface of the cover plate 16 on opposite sides of the notches 12, inthe uppermost positions of the bolts 13, whereby the cover plate 10 issecured to the casing section 2.

A vertically disposed cylindrical member 29 is surrounded by the annularcover plate 141, and is welded thereto intermediate its ends. The insidediameter of the cylindrical member Ztl is reduced by stages near itslower end to form a pair of upwardly facing internal shoulders 21 and22;, which are spaced vertically relative to each other. An annularclosure member 23, which is received in the upper end of the cylindricalmember 211, has a radially outwardly extending flange 2 which isconnected by screws 25 to the upper edge of the cylindrical member 20.

A vertically disposed sleeve 26 is arranged concentrically within thecylindrical member 20, and is rotatably supported therein as hereinafterdescribed. The upper end of the sleeve 26 is surrounded by the annularclosure member 23, and the lower end of the sleeve 26 extends downwardlybelow the cylindrical member Zll.

A flange 27 is formed on the sleeve 26 intermediate its ends, andextends radially outwardly therefrom. A pair of thrust bearings, each ofwhich consists of an inner race ring 28, an outer race ring 239, and aplurality of tapered roller bearings 30, support the sleeve 26 forrotative movement relative to the cylindrical member 2th whilepreventing longitudinal movement of the sleeve 26 relative to thecylindrical member 25). The inner race rings 23 surround the sleeve 26and are positioned on opposite sides of the flange 27. The outer racerings 29 are received within the cylindrical member 26 and arepositioned immediately above the uppermost internal shoulder 21, andimmediately below the annular closure member 23, respectively.

A sealing ring 31, which is received in an annular recess providedtherefor in the upper surface of the annular closure member 23, providesa seal between the annular closure member 23 and the sleeve 26. A pairof sealing rings 32., which are positioned one above the other withinthe cylindrical member 20, between the internal shoulders 21 and 22,provide a seal between the cylindrical member 20 and the sleeve 26 toconfine the lubricants introduced to the bearings 3t A lubricatingfitting 33, which is attached to the top side of the annular closuremember 23, communicates with a fluid passage 34 extending through theannular closure member 23, whereby the bearings 30 may be lubricated. Alubricating fitting 35, which is attached to the top side of the annularcover plate 11 communicates with a tube 36 which is connected at itsends to annular cover plate 10 and the cylindrical member Ztl and isadapted to supply a lubricant to the interior of the cylindrical member26, between the sealing rings 32.

The sleeve 26 has a pair of arcuate projections 37 extending radiallyinwardly from two opposite sides thereof, adjacent its upper end. A plug38, which is received within the sleeve 26, has a flange 39 extendingradially outwardly therefrom, adjacent its upper end, for abutmentagainst the upper end of the sleeve 26 whereby the plug 38 is supportedon the sleeve 26. The

plug 38 has a pair of arcuate projections 44 extending radiallyoutwardly from two opposite sides thereof, for abutment against thearcuate projections 37 to limit rotative movement of the plug 38relative to the sleeve 26. The plug 38 has a square opening 41 in thecenter thereof adapted to receive a section of square drill pipe 42,commonly referred to as a kelly, whereby the sleeve 26 is rotated withthe kelly 42.

The sleeve 26 is threaded externally adjacent its lower end forengagement by a ring 43, which is threaded internally and externally andis received thereon. The ring 43 is flanged internally adjacent itslower end to form an upwardly facing internal shoulder 44 for abutmentagainst the lower end of the sleeve 26 to limit the upward movement ofthe ring 43 relative to the sleeve 26.

A pair of circular diaphragms 45 and 46, which are formed of flexible,elastic material and have central openings 47 and '48 therein throughwhich the kelly 42 is passed, are secured at their edges, in juxtaposedrelation to each other, between the ring 43 and a ring 49, which isthreaded internally for engagement with the ring 43, and is receivedthereon. The ring 49 is flanged internally adjacent its lower end toform an upwardly facing internal shoulder 50 for abutment against theunder side of the lowermost diaphragm 46, whereby the diaphragms 45 and46 are clamped between the rings 43 and 49.

The diaphragms 45 and 46 are secured in concentric relation to the ringsS3 and t9 by a plurality of circumferentially spaced threaded pins 51,which are secured in threaded openings provided therefor in the underside of the ring 43 and are received in aligned openings pro videdtherefor in the diaphragms 45 and 46.

The lowermost diaphragm 46 has a depressed central portion 52surrounding the central opening 48, which is square and conformssubstantially to the shape of the kelly 42. The opening 48 preferably isslightly smaller than the cross-sectional area of the kelly 42, so thatthe material of the diaphragm 46 surrounding the opening 48 is stretchedupon passing the kelly 42 through it. Thus the diaphragm -46frictionally engages the kelly 42 and provides an effective seal betweenthe kelly 42 and the sleeve 26.

The central opening 47 of the uppermost diaphragm 45 is round, andconforms substantially to the shape of a round section of drill pipe 53,shown in dotted lines in FIGURE 5, which is interchangeable with thekelly 42. The opening 47 preferably is slightly smaller than the crosssectional area of the pipe 53, so that the material of the diaphragm 45surrounding the opening 47 is stretched upon passing the pipe 53 throughit. Thus the diaphragm 45 frictionally engages the pipe 53 and providesan effective seal between the pipe 53 and the sleeve 26.

In operation, the plug 38 positively insures rotation of the sleeve 26with the kelly 42, and thus avoids the possibility of rupturing thelowermost diaphragm 46, due to torque applied thereto, When employingthe square drill pipe or kelly 42. While the uppermost diaphragm 45'frictionally engages the round pipe 53, so that the sleeve 26 normallyrotates with the pipe 53, the diaphragm 45 would not be damaged if forany reason the sleeve 26 is prevented from being rotated with the pipe53. Thus the plug 38 is not required when using the pipe 53.

An annular plate 54 is threaded internally for engage ment with theexternally threaded lower end of the sleeve 26, and is received thereon.The annular plate 54. is positioned above the ring 43, in spaced apartrelation thereto.

The annular plate 54 is enclosed in an annular housing 55, and isrotatable relative thereto. The annular housing 55 has a peripheral wall56 having a diameter conforming substantially to the inside diameter ofthe casing section 2 and top and bottom portions 57 and 58 which areclosely spaced relative to the annular plate 54 and loosely surround thesleeve 26. The bottom portion 58 of the annular housing 55 is formedintegrally with the peripheral wall 56. The top portion 57 is receivedin an annular recess 59 provided therefor in the peripheral wall 56, andis welded thereto.

The annular plate 54 is spaced apart from the top and bottom portions 57and 58 of the annular housing 55 by a plurality of short verticallydisposed, circumferentially spaced pins 60, which are attached toopposite sides of the annular plate 54- and slidably engage the top andbottom portions 57 and 58 of the annular housing 55 upon rotation of theannular plate 54 relative to the annular housing 55.

The annular housing 55 is supported on a ring 61, which is welded to theinner wall of the casing section 2. A plurality of circum'ferentiallyspaced, radially extending lugs 62, which are attached to the under sideof the annular housing 55, are received in corresponding slots 63provided therefor in the upper surface of the ring 61, whereby theannular housing 55 is prevented from being rotated relative to thecasing section 2.

A pair of resilient 0 rings 64 are received in peripheral grooves 65provided therefor in the exterior surface of the peripheral wall 56 ofthe annular housing 55, in spaced apart relation to each other. The 0rings 64 provide a seal between the annular housing 55 and the casingsection 2 and effectively prevents the passage of drilling fluidtherethrough and about the housing 55.

A lubricating fitting 66, which is attached to the exterior surface ofthe casing section 2, communicates with a fluid passage 67 formed in theperipheral wall 56 of the annular housing 55, between the peripheralgrooves 65, whereby a lubricant may be introduced into the interior ofthe annular housing 55. The lubricant so introduced lubricates the pins60, and in addition, provides a seal between the annular plate 54 andthe annular housing 55, which in turn seal the annular space between thesleeve 26 and the casing section 2. The plate 54, as stated, isthreadedly secured to the sleeve 26 and rotates therewith, thusproviding a barrier, with the lubricant in the housing 55, against thepassage of drilling fluid to the area above the housing 55.

The invention may be modified in various ways without departing from thespirit and scope thereof.

What is claimed is:

1. In a well head for air drilling apparatus for wells, in combinationwith a well casing and a drill pipe in said casing, a drilling headcomprising, in combination, a cylindrical collar adapted to be attachedto said casing and having a fluid outlet on one side thereof, a flangedcylinder rigidly supported by and concentrically of said collar, asleeve rotatively supported on bearings in said cylinder and a drillpipe adapter plug seated thereon and rotatable therewith, an annularhousing secured in said collar about said sleeve above said fluid outletand adapted to retain a sealing lubricant and a ring fixed to the innerwall of said collar for supporting said annular housing, a plurality ofsealing rings arranged peripherally of said annular housing in saidcollar, an annular plate threadedly secured to said sleeve and enclosedin said annular housing and rotatable between the top and bottom thereofwhereby to provide a fluid-tight seal above said fluid outlet, and adiaphragm secured to the lower end of said sleeve embracing the saiddrill pipe and providing a seal thereabout.

2. In a drilling head for use with compressed air as a drilling fluid,in combination with a Well casing and a drilling pipe, a collar havingconnection with the well casing and having a fluid outlet on one side, aflanged cylinder supported by said collar concentrically thereof, asleeve rotatively mounted in said cylinder above said fluid outlet, adrill pipe adapter plug rigidly seated in the top of said sleeve wherebyto rotate the same when said drill pipe is rotated, an annular platethreadedly attached to the lower end of said sleeve above said fluidoutlet, a relatively fiat stationary annular housing for said annularplate attached to said collar and adapted to retain a sealing lubricantabout said annular plate as the latter is rotated therein, a ring insaid collar for supporting said an nular housing therein, a plurality ofsealing rings arranged peripherally of said annular housing and engagingthe inner wall of said collar, and means comprising a diaphragm securedto the lower end of said sleeve and embracing said drill providing aseal thereabout above said fluid outlet.

3. In a drilling head as described in claim 2, wherein the said sleeveis rotatably mounted concentrically of said cylinder, and said annularplate is spaced above and below the bottom and top annular Walls of saidannular housing.

4. In a drilling head for drilling well bores with compressed air as adrilling fluid, in combination with a Well casing and a drilling pipe, acollar attached to the top of said well casing and having a fluid outleton one side, a flanged cylindrical member rigidly supported by andconcentrically of said collar and having a cover secured thereto, asleeve rotatably supported on a plurality of bearings in saidcylindrical member above said fluid outlet, a drill pipe adapter seatedin the upper end of said sleeve, a diaphragm secured about the lower endof said sleeve above said fluid outlet and engaging said drill pipe andproviding a seal therearound, an annular housing secured on a ringarranged internally of said collar and embracing said sleeve, sealingmeans arranged peripherally of said annular housing, an annular platesecured about said sleeve and extending laterally into said annularhousing, and means for injecting a sealing lubricant into said housingand about said annular plate to lubricate and seal the same.

5. 'In a drilling head for oil Wells as described in claim 4, acylindrical member supported in said collar and a bearing supportarranged internally thereof, and a hearing in said cylindrical memberrotatably supporting said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS1,708,316 MacClatchie Apr. 9, 1929 2,126,007 Guiberson Aug. 9, 19382,170,916 Schweitzer Aug. 29, 1939 2,222,082 Leman Nov. 19, 19402,243,340 Hild May 27, 1941 2,646,999 Barske July 28, 1953

